BigJigs Wooden Railway Diesel Engine BJT414 BigJigs diesel engine is a brighly colored addition to your wooden railway system. With wheels that steer, the engine goes around curves smoothly. Magnetic couplings ensure compatibility with all other engines and carriages in the BigRigs Rail collections. Most wooden railway sets are compaitble with BigJigs Rail, making BigJigs the perfect choice for starting or expanding your collection. Ages 3+.